Active Standard ASTM D7559 / D7559M | Developed by Subcommittee: D13.20
Book of Standards Volume: 07.02
Significance and Use
This test method may be used for product development and design, production validation, manufacturing process control, lot acceptance, or for a combination thereof.
The rate of inflation in this method does not attempt to mimic that of an actual cushion deployment, nor is it intended to subject the cushion to the dynamic loads, stress, and temperatures during such an event. It is also recognized that the compressed air used for this tests may not leak through the cushion at the same rate as the gas or mixture of gasses typically used in cushion inflators. Rather this method is intended to give a relative indication of the pressure holding ability of the cushion.
The internal volume and internal design of cushions varies greatly. This test method is most useful when comparing data from cushions of the same design and volume. This test method does not provide any data concerning the volume of gas leaking from the bag. At certain higher levels of the initial internal pressure, this test method will irreversibly damage the cushion and change its leakage properties for future testing or for commercial use. The damage to the bag is dependent on the design or shape of a specific bag and the type of coating applied. It is the responsibility of the supplier and / or purchaser to determine if the parameters under which a cushion is tested will be destructive and render the cushion unfit for future use
Within the limits of variance expressed in Section 12, this test method is useful for design and production validation and may be suitable for incorporation in a cushion specification or for lot acceptance testing of commercial shipments.
1.1 This test method is intended to determine the ability of an inflatable restraint cushion to retain air pressure at elevated pressures for a specified time interval.
1.2 Procedures and apparatus other than those stated in this test method may be used by agreement of purchaser and supplier, provided the specific deviations from the standard acknowledged in the report.
1.3 The results of this test method should not be used to predict the actual internal pressure decay of a cushion during a deployment.
1.4 The values stated in either SI units or inch-pound units are to be regarded separately as standard. The values stated in each system may not be exact equivalents; therefore, each system shall be used independently of the other. Combining values from the two systems may result in non-conformance with the standard.
1.5 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety and health practices and determine the applicability of regulatory limitations prior to use.
2. Referenced Documents (purchase separately) The documents listed below are referenced within the subject standard but are not provided as part of the standard.
D123 Terminology Relating to Textiles
D6799 Terminology Relating to Inflatable Restraints
E691 Practice for Conducting an Interlaboratory Study to Determine the Precision of a Test Method
ICS Number Code 43.040.80 (Crash protection systems and restraint systems)